JP2005299624A - Engine muffler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine muffler for actualizing high output, high speed rotation, improved fuel consumption and clean exhaust gas while solving problems on a mini-vehicle of 550cc displacement which has poor acceleration, no speed increase and bad mileage wherein such a phenomenon appears that it is followed by more vehicle when running on a slope and it cannot turns aside to the left on a mountain road because there are less spaces, overtaking lanes and by-lanes. <P>SOLUTION: As shown in Fig., compressed exhaust gas is accelerated while being delivered from an exhaust port at the rearmost portion of a chamber straightly via a space into a center pipe 3 or a somewhat larger pipe and it is further accelerated at a position of an outlet 14 of a second chamber. Thus, the exhaust gas highly compressed in a first chamber c7 and pushed out of a hole 13 is inhaled into the center pipe 3 at a position 14. Considerable temperature rise occurs in the second chamber 4, which shows the effect of complete combustion. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an engine muffler.

  In a two-cycle engine, a scavenging action is performed to expel exhaust gas generated by combustion of the air-fuel mixture in the combustion chamber with fresh air, and the time during which the intake pipe, the combustion chamber, and the exhaust pipe are in communication with each other is relatively long. Therefore, fresh air blows through or exhaust gas remains in the combustion chamber more than necessary, adversely affecting performance. The new air is prevented from being blown through and the scavenging efficiency is improved.

  That is, in the two-cycle engine, there is a period when the new blow-through charging efficiency decreases after the scavenging port is closed until the exhaust port is closed. During this period, the exhaust period internal pressure in the vicinity of the exhaust port is higher than the cylinder internal pressure. In addition, it is desirable that the scavenging air flow easily while the scavenging port is open and the exhaust pipe internal pressure near the exhaust port is set to a negative pressure.

  Therefore, an expansion chamber for effectively utilizing the arterial effect due to the exhaust pressure is formed in the exhaust pipe of the two-cycle engine, and a positive pressure is generated near the exhaust port just before the exhaust port is closed by the arterial effect due to the expansion chamber. While the reflected wave returns and the scavenging port is open, a negative reflected wave near the exhaust port returns.

  By the way, the pressure wave propagates through the exhaust pipe at the speed of sound, and the speed of sound is proportional to the temperature (exactly proportional to the square root of the absolute temperature). It is necessary to increase the exhaust sound and increase the propagation speed of the exhaust pressure wave.

  Therefore, as a method of increasing the exhaust temperature in the high rotation range, a method of delaying the ignition timing or covering the exhaust pipe with a heat insulating material or a cover to keep the temperature warm has been adopted.

  The two-cycle engine performs two-stroke movement of the piston, that is, the intake, compression, explosion, and scavenging operations during one rotation of the crankshaft, and generates power by repeating these operations. In a two-cycle engine, the upward stroke of the piston is a stroke for compressing the air-fuel mixture, and the downward stroke is an explosion stroke for generating power, and the compression and the explosion stroke are performed in the same manner as the four-cycle engine. Unlike there is no separate process for intake and exhaust.

The 2-cycle engine does not use valves like the 4-cycle engine, and it has the advantage of being simple and lightweight and easy to handle. On the other hand, part of the air-fuel mixture is discharged unburned during exhaust. The fuel consumption rate is large, the operation is uncertain, and the rotation efficiency is poor. Conventionally, the concept of complete combustion by repeatedly returning unburned gas exhausted into the muffler to the combustion chamber Was not taken.
JP-A-10-212943 JP-A-9-273431

  However, the method of increasing the exhaust gas temperature by retarding the ignition timing in the high engine speed range reverses the amount of combustion deterioration because the combustion of the air-fuel mixture deteriorates and the exhaust gas temperature decreases while the exhaust pipe temperature is low. In addition to being effective, excessive retardation of the ignition timing causes an abnormal temperature rise of the exhaust and causes various problems.

  In addition, while the temperature of the exhaust pipe can be reliably increased, the temperature of the exhaust pipe and the exhaust gas can be reliably increased. However, since the temperature of the exhaust pipe and the exhaust gas is increased in the entire rotation range, the exhaust pulsation is suppressed in the low rotation range. There arises a problem that mis-mating occurs and performance deteriorates.

  A two-cycle light car with a displacement of 550 cc is not accelerating, does not produce speed, and has poor fuel consumption. To provide an engine muffler that enables high output, high speed, and improved fuel efficiency.

  If the flow of exhaust gas in the muffler is slow, the combustion speed will also be slow if the flow of intake air is slow, and the temperature in the muffler will drop, and if it falls, the incomplete combustion debris will accumulate on the inner surface of the muffler and gradually increase the inner area Becomes narrower. A two-cycle engine can become immobile, which is much lower than the initial performance. It is necessary to always maintain the inner area by complete combustion.

  In order to achieve the above object, the invention according to claim 1 has a structure in which the rear part of the expansion chamber of the muffler has a two-chamber structure, that is, creates a space between the outlet of the rear part of the chamber and the center pipe, and surrounds it with a cylinder, The engine muffler has a two-chamber structure that generates jet airflow. A round cylinder is put on the rear part of the chamber and a lid is formed to create a space between the rear part of the chamber and the center pipe. As soon as the exhaust gas expanded and compressed is released at once, the speed is increased and further exhaust gas is taken up.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, a round tube is provided at the rear portion of the chamber, wherein the expansion chamber of the muffler has a two-chamber structure to increase the heat retaining effect and to enable complete combustion. The cover is increased to increase the exhaust pressure in the chamber and protect the part where the exhaust heat rises.

  In the invention of claim 3, in the invention of claim 2, a large number of holes are made in the expansion chamber and the chamber rear portion, and excessive pressure in the expansion chamber at the time of high rotation can be directly emitted from the outlet at the rear of the chamber. The exhaust gas that has become impossible to escape temporarily to the second chamber, and it is directly sucked into the air flow of high-pressure exhaust gas from the chamber outlet, so that the exhaust efficiency is further improved. . That is, if a large number of small holes are made in the rear of the chamber body and a rapid high rotation is applied, a considerable exhaust pressure is applied. If this is left as it is, the resistance becomes bad and the rotation decreases. In order to eliminate these problems, a hole is made in a portion where the pressure is highest, so that the pressure can be adjusted appropriately.

  As is apparent from the above description, according to the first or second aspect of the present invention, the exhaust gas that has been made into a room and has been completely burned in the warming room is further accelerated and exits as clean exhaust gas. can get.

  Further, according to the invention described in claim 3, although it was difficult to grow in the high rotation range, a good elongation was born because the excess pressure was moderately removed by countless holes. However, when high rotation is good, low rotation is usually poor, but with the combination of chamber and hole, it is moderately resisted by a narrow conical wall that is narrow at low rotation, and at high rotation, there are countless hole effects. The excess exhaust pressure is discharged to the outside room, and the effect of being sucked into the sonic airflow of the high-pressure exhaust gas having the effect obtained in claims 1 and 2 is obtained.

  Thus, the exhaust speed in the muffler is increased, the suction effect is improved, the engine speed is increased, and the engine performance can be improved.

  The temperature inside the muffler also rose by nearly 20 degrees, resulting in exhaust near exhaustion and almost no white smoke. The uphill of the mountain road will also accelerate, and even if you want to overtake it, you can not overtake it, you can be in the opposite position.

  Embodiments of the present invention will be described. In the two-cycle engine, the scavenging port opens a little after the exhaust hole is opened, and the pre-compressed air-fuel mixture flows into the combustion chamber above the cylinder through the scavenging port and expels the combustion gas in the combustion chamber. Works. This is the scavenging action, and this process is the heart of the two-cycle engine. However, at that time, a new air-fuel mixture is also discharged with combustion, which is a factor of exhaust pollution.

  The present invention increases engine output and is close to pollution-free exhaust gas. It is the greatest form of success that it creates a space between the back of the chamber and the center pipe and surrounds it with the chamber.

  An embodiment of the present invention will be described with reference to the accompanying drawings and FIG. 2. A chamber body is 1, a space is formed between the chamber rearmost portion 12 and the center pipe 3, surrounded by a cylinder 8, and a lid 9 is formed. By providing the second chamber 4, the exhaust gas having a high flow velocity goes out from the exhaust port 12 to the center pipe 3.

  Then, the last part of the chamber 1, the first chamber c 7, was provided with the second chamber 4 with the cylinder 8 and the lid 9, and a heat retention effect was produced and a complete combustion effect was also produced.

  In addition, by opening a large number of holes 13 (the number varies depending on the engine displacement and engine performance) in the first chamber c7 at the rear of the chamber in FIG. 2, the engine performance can be stably rotated from low to high. . This is because the hole 13 is opened and the exhaust gas is stable because the wall of the rear first chamber c7 of the chamber is gradually narrowed at a low rotation, and at a high rotation, the exhaust gas is completely exhausted at the small hole 12 at the end of the chamber. Can't escape. Therefore, since it escapes moderately from the plurality of holes 13 at the rear, high rotation is also stabilized.

  Here, since the exhaust gas pushed out from the hole 13 at the rear of the chamber is drawn into the high-pressure fast exhaust gas that has come out straight at the location of the second chamber outlet 14, a synergistic effect has been produced.

  In the case of a commercial engine and muffler, white smoke is always emitted from the end of the muffler during running, but when this muffler was installed, it would not come out when the water temperature (rajeter) approached 50 degrees after warming up.

  On average, the maximum speed was only 65 to 75 kilometers per hour, but now it is running at 80 to 95 kilometers per hour.

It is explanatory drawing which showed the whole plane of the muffler. It is explanatory drawing which showed the cross section of the left side surface of a chamber.

Explanation of symbols

1 Chamber 2 Silencer 3 Center pipe 4 Second chamber 5 First chamber a
6 Room 1 b
7 Room 1 c
8 Cylinder 9 Lid 12 Exhaust port 13 Hole 14 Second chamber outlet

Claims (3)

  Exhaust chamber of the muffler The muffler has a structure in which the rear part of the chamber has a two-chamber structure, that is, a space is created between the outlet of the rear part of the chamber and the center pipe, and the circumference is surrounded by a cylinder. .   The muffler according to claim 1, wherein the rear part of the expansion chamber chamber of the muffler has a two-chamber structure so as to increase the heat insulation effect and allow complete combustion.   A large number of holes are made in the rear part of the expansion chamber and the chamber, and the exhaust gas that cannot be discharged directly from the outlet at the rear of the chamber due to excessive pressure in the expansion chamber during high rotation is temporarily stored in the second chamber. 3. A muffler according to claim 2, wherein the exhaust efficiency is further improved by exhausting the air into a high-pressure exhaust gas stream exiting from the chamber outlet.

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